Afinidades (2010)
A physicist whose job might be at risk agrees to swap wives with his boss. Individual feelings might get in the way.
swinging or open relationship but husband/bf gets jealous
Pleasure Party (1975) aka Une partie de plaisir
Phillipe and Esther live an apparently idyllic life with their daughter, Elise. In an attempt to preserve this bliss, Phillipe decides that he and Esther should each have affairs, being sure to tell each other openly about them. The plan backfires with tragic results as Phillipe becomes engulfed in jealously.